Józef Światło, born Izaak Fleischfarb (1 January 1915 – 2 September 1994), was a high-ranking official in the Ministry of Public Security of Poland (UB) who served as deputy director of the 10th Department run by Anatol Fejgin.

[1] After the 1953 death of Joseph Stalin and arrest of Lavrentiy Beria, Światło traveled to East Germany on official business.

Józef Światło was born on 1 January 1915 as Izaak Fleischfarb (also Fleichfarb, Licht, or Lichtstein, sources vary),[a] into a Jewish family in Medyn village near Zbarazh in Galicia (now Ukraine).

[1] In 1945, he was transferred to the newly formed Ministry of Public Security of Poland (officially MBP, but commonly abbreviated to UB).

[1] He received orders personally from the First Secretary of the Polish United Workers' Party Bolesław Bierut, and arrested such notable people as politicians Władysław Gomułka[1] and Marian Spychalski,[4] General Michał Rola-Żymierski,[1] and Cardinal Stefan Wyszyński.

[1] In November 1953, the First Secretary of the Polish United Workers' Party Bolesław Bierut asked Politburo member Jakub Berman to send Światło on an important mission to East Berlin.

Światło, deputy head of UB's 10th Department, together with Colonel Anatol Fejgin, were asked to consult with Stasi chief Erich Mielke about eliminating Wanda Brońska [pl].

The next day, American military authorities transported Światło to Frankfurt and by Christmas he had been flown to Washington, D.C., where he underwent an extensive debriefing.

Over the course of the following months, US newspapers and RFE (in the "Behind the Scenes of the Secret Police and the Party" cycle) reported extensively on political repression in Poland based on Światło's revelations.

[1] Światło detailed the torture of prisoners under interrogation and politically motivated executions and struggles inside the Polish United Workers' Party.